* U.N. aid chief says saw mortars land on Syrian side of border
* Says need an agreement by rebels and army not to attack refugees
* Wants political solution needed by international community
By Suleiman Al-Khalidi
ZAATARI, Jordan, Nov 27 (Reuters) - The United Nations humanitarian chief accused Syria on Tuesday of firing mortar bombs near the border with Jordan to prevent refugees from fleeing a civil war that she says is "getting worse day by day".
In an interview with Reuters at the Jordanian refugee camp of Zaatari on Tuesday, Valerie Amos said that during a visit to the border the night before she was able to see "what was definitely mortar fire on the Syrian side of the border to try to prevent people from crossing."
Opposition activists say 40,000 people have been killed in the revolt against the rule of Bashar al-Assad, which started out as peaceful protests 20 months ago only to descend into full civil war.
Almost half a million refugees have fled into Turkey, Lebanon, Jordan and Iraq as the fighting has spread and more are expected as winter approaches.
"We need the agreement by all those involved in the conflict to ensure they will not in any way bomb or shell or fight (refugees)," Amos said.
30,000 people live in the windswept Zaatari camp - half of them children - and some tents are being replaced with 2,000 more permanent prefabricated homes. In the months since Zaatari opened it has come to resemble a shanty town with small vendors now selling fresh vegetables and second-hand clothes.
Amos talked to refugees, some of whom complained they had few blankets at the start of the biting winter cold and were not getting enough food.
"You can see the anger, fear and resentment. There is considerable trauma here," Amos said during her visit.
50 PERCENT FUNDED
World powers are divided over the crisis and have been unable so far to agree on action to halt the violence, with Assad's allies Russia and China having vetoed three United Nations Security Council resolutions.
"We will do all we can to help the refugees and people of Syria but this requires the international community to work together to find a political solution which meets the needs of the Syrian people," Amos said.
She said that a U.N. appeal for Syria's 2.5 million internally displaced people has only been 50 percent funded, and that the world body was planning for numbers of up to 4 million.
"Given the intensification of the violence inside Syria I am sure they will go up in the next few weeks," she added.
Amos said that through partner bodies including the World Food Programme and the Syrian Arab Red Crescent, food is being supplied to 1.5 million people. But that the United Nations need more partner organisation to reach the displaced.
"We would like to be able to increase that to 2.5 million people but we do not have the capacity through the partners we are able to use," she said.
Aid organisations in Syria have complained of severe government restrictions on movement and Amos said that over 50 percent of healthcare facilities had been damaged during the conflict.
"I am extremely worried about it, the situation is getting worse and it's ordinary people who are bearing the brunt of this violence and we are appealing to the international community to support the Syrian people and to find a resolution to this as soon as possible." (Writing by Oliver Holmes; Editing by Greg Mahlich)